1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
ivann1987 [24]
3 years ago
13

X+3y-2z=10, -x-2y+z=-7, 3x+9y-5z=28

Mathematics
2 answers:
NISA [10]3 years ago
6 0
Hmm
what you do is try to eliminate 1 variable in 2 equaions first
we can elminate x's in first and 2nd equation

add first and 2nd equation
x+3y-2z=10
<u>-x-2y+z=-7 +</u>
0x+y-z=3
y-z=3


multiply 2nd equation by 3 and add to last one
-3x-6y+3z=-21
<u>3x+9y-5z=28 +</u>
0x+3y-2z=7

3y-2z=7

we now have
y-z=3
3y-2z=7
multiply first equation by -2 and add to 2nd

-2y+2z=-6
<u>3y-2z=7 +</u>
y+0z=1
y=1

now we can sub back
y-z=3
1-z=3
minus 1
-z=2
times -1
z=-2

sub baack into any equation
x+3(1)-2(-2)=10
x+3+4=10
x+7=10
minus 7
x=3

x=3
y=1
z=-2
(3,1,-2)

Semenov [28]3 years ago
4 0
  
\displaystyle  \\ &#10;~~~~x+3y-2z=10 ~~~~~(E_1)\\  &#10;-x-2y+z=-7 ~~~~~(E_2)\\ &#10;~~3x+9y-5z=28~~~~~(E_3) \\ &#10;\text{- - - - - } \\ &#10;E_1 + E_2 ~~\Longrightarrow~~y - z = 3 \\  \\ &#10;-3 \times E_1  + E3  ~~\Longrightarrow~~ z = -2 \\  \\ &#10;\Longrightarrow\Longrightarrow\Longrightarrow \\  \\ &#10;y-z=3\\&#10;z = \boxed{-2}\\&#10;\text{- - - - - }\\&#10;y-(-2)=3\\&#10;y+2=3\\&#10;y =3-2=\boxed{1}\\&#10;\text{- - - - - }\\&#10;x+3y-2z=10\\&#10;x+3\cdot 1-2\cdot (-2)=10\\&#10;x+3+4=10\\&#10;x+7=10\\&#10;x= 10 - 7 = \boxed{3}



You might be interested in
Solve the equation. q+5/9=1/6
Irina-Kira [14]

Answer:

−7/18

Step-by-step explanation:

Subtract 5/9  from both sides of the equation

6 0
3 years ago
A recipe uses 2 cups of sugar to make 32 brownies. How many cups of sugar are needed to make 72 brownies?
White raven [17]
4 and a fourth. This is because 2 * 32 is 64, then you need to divide 32 by 4 to get 8 left. I am sorry if I solved this incorrectly. Make sure to check with your coordinator ( teacher ) or parent to help solve this. 32 is divided into 4ths.
5 0
3 years ago
The proof that ΔACB ≅ ΔECD is shown. Given: AE and DB bisect each other at C. Prove: ΔACB ≅ ΔECD What is the missing statement i
GarryVolchara [31]

Answer:

The missing statement is ∠ACB ≅ ∠ECD

Step-by-step explanation:

Given two lines segment AC and BD bisect each other at C.

We have to prove that ΔACB ≅ ΔECD

In triangle ACB and ECD

AC=CE    (Given)

BC=CD   (Given)

Now to prove above two triangles congruent we need one more side or angle

so, as seen in options the angle ∠ACB ≅ ∠ECD due to vertically opposite angles

hence, the missing statement is ∠ACB ≅ ∠ECD


9 0
3 years ago
Read 2 more answers
What is the perimeter of a triangle measuring 3 on each side?
ANTONII [103]
Add them all up.
A triangle has 3 sides, and you said each side is 3. So:
3+3+3 = 9
8 0
3 years ago
Read 2 more answers
Lucy made $323 for 17 hours of work.
saveliy_v [14]
19 minutes I think just divide 323 and 17
3 0
3 years ago
Other questions:
  • How do I solve... a for this equation? What steps should I take to solve it?<br><br> 2B(F+a)=H
    8·1 answer
  • BEST ANSWER GETS BRAINLIEST!! PLEASE HELP
    14·2 answers
  • It takes Henry 3 hours to paint someone’s portrait how many hours would it take for him to paint all 8 of his friends’ portraits
    10·2 answers
  • Graph the line whose y intercept is 9 and whose x intercept is 4
    14·1 answer
  • Suppose you select a sample of 12 individuals and find that 10 of them do not exercise regularly. Assuming that the Surveillance
    13·1 answer
  • Find the equation of the quadratic function with zeros 10 and 12 and vertex at (11, -2).
    11·1 answer
  • suppose the monkey is typing using only the 26 letter Keys what is the probability that the monkey will type cat
    7·1 answer
  • 3. Evaluate the expression. If k = 3 and h = 2. (Be sure to show each step)<br> 4k+2(5k-2)-h
    5·1 answer
  • I need help with this one please
    6·2 answers
  • Calculate the volume of the rectangular prism
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!